The spine is a flexible column formed of a plurality of bones called vertebrae. The vertebrae are hollow and piled one upon the other forming a strong hollow column for support of the cranium and trunk. Various spinal disorders such as scoliosis, neuromuscular disease, and cerebral palsy may cause the spine to become misaligned, curved, and/or twisted or result in fractured and/or compressed vertebrae. It is often necessary to introduce an interbody device to fuse adjacent vertebra together to help correct the spinal disorder.
The introduction of an interbody device such as an implant, may be done using a minimally invasive procedure with a lateral approach. In general, minimally invasive procedures use a retractor. The retractor includes a plurality of retractor blades which cooperate with each other to form a generally tubular opening. The retractor blades are inserted into the body and radially displaced from each other so as to form a surgical corridor leading from a small incision on the skin to the surgical site.
Currently, retractors include at least two retractor blades which when closed together form a cylindrical tube. The retractor is introduced into the surgical site and gradually expanded by positioning the retractor blades apart from one another. A tremendous load is placed on the distal end of the retractor blades by surrounding muscles and ligaments, a phenomena known as “musculature load.” Musculature load works to bend the retractor blades and close the distal end of the surgical corridor. Accordingly, the retractor blades are currently formed of a durable and rigid metal to help withstand the musculature load. The interbody device is then passed through the surgical corridor. Since the window of view is narrow through the surgical corridor, it is known to use an x-ray machine to help guide the placement of the interbody device. However, the metallic retractor blades can interfere with the x-ray's ability to view the interbody device.
Accordingly, it remains desirable to have a retractor system configured to withstand the musculature load but have retractor blades which are radio transparent so as to facilitate the view of the interbody device by the x-ray machine.